Using high-speed cameras, MIT researchers observed that when a raindrop hits a surface, it traps tiny air bubbles at the point of contact. The bubbles then shoot upward, ultimately bursting from the drop in a fizz of aerosols. The researchers suspect that in natural environments, aerosols may carry aromatic elements, along with bacteria and viruses stored in soil. These aerosols may be released during light or moderate rainfall, and then spread via gusts of wind.